diff options
Diffstat (limited to 'lib/option.mli')
| -rw-r--r-- | lib/option.mli | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/lib/option.mli b/lib/option.mli index 6fa89098..ef2e311a 100644 --- a/lib/option.mli +++ b/lib/option.mli @@ -6,7 +6,7 @@ (* * GNU Lesser General Public License Version 2.1 *) (************************************************************************) -(* $Id: option.mli 11576 2008-11-10 19:13:15Z msozeau $ *) +(* $Id$ *) (** Module implementing basic combinators for OCaml option type. It tries follow closely the style of OCaml standard library. @@ -18,7 +18,7 @@ (** [has_some x] is [true] if [x] is of the form [Some y] and [false] otherwise. *) val has_some : 'a option -> bool - + exception IsNone (** [get x] returns [y] where [x] is [Some y]. It raises IsNone @@ -37,7 +37,7 @@ val flatten : 'a option option -> 'a option (** {6 "Iterators"} ***) -(** [iter f x] executes [f y] if [x] equals [Some y]. It does nothing +(** [iter f x] executes [f y] if [x] equals [Some y]. It does nothing otherwise. *) val iter : ('a -> unit) -> 'a option -> unit @@ -66,6 +66,9 @@ val fold_left2 : ('a -> 'b -> 'c -> 'a) -> 'a -> 'b option -> 'c option -> 'a (** [fold_right f x a] is [f y a] if [x] is [Some y], and [a] otherwise. *) val fold_right : ('a -> 'b -> 'b) -> 'a option -> 'b -> 'b +(** [fold_map f a x] is [a, f y] if [x] is [Some y], and [a] otherwise. *) +val fold_map : ('a -> 'b -> 'a * 'c) -> 'a -> 'b option -> 'a * 'c option + (** [cata e f x] is [e] if [x] is [None] and [f a] if [x] is [Some a] *) val cata : ('a -> 'b) -> 'b -> 'a option -> 'b @@ -77,15 +80,15 @@ val default : 'a -> 'a option -> 'a (** [lift] is the same as {!map}. *) val lift : ('a -> 'b) -> 'a option -> 'b option -(** [lift_right f a x] is [Some (f a y)] if [x] is [Some y], and +(** [lift_right f a x] is [Some (f a y)] if [x] is [Some y], and [None] otherwise. *) val lift_right : ('a -> 'b -> 'c) -> 'a -> 'b option -> 'c option -(** [lift_left f x a] is [Some (f y a)] if [x] is [Some y], and +(** [lift_left f x a] is [Some (f y a)] if [x] is [Some y], and [None] otherwise. *) val lift_left : ('a -> 'b -> 'c) -> 'a option -> 'b -> 'c option -(** [lift2 f x y] is [Some (f z w)] if [x] equals [Some z] and [y] equals +(** [lift2 f x y] is [Some (f z w)] if [x] equals [Some z] and [y] equals [Some w]. It is [None] otherwise. *) val lift2 : ('a -> 'b -> 'c) -> 'a option -> 'b option -> 'c option @@ -105,8 +108,8 @@ end (** {6 Miscelaneous Primitives} *) module Misc : sig - (** [Misc.compare f x y] lifts the equality predicate [f] to - option types. That is, if both [x] and [y] are [None] then + (** [Misc.compare f x y] lifts the equality predicate [f] to + option types. That is, if both [x] and [y] are [None] then it returns [true], if they are bothe [Some _] then [f] is called. Otherwise it returns [false]. *) val compare : ('a -> 'a -> bool) -> 'a option -> 'a option -> bool |